


The Mona Lisa.

by ProtoGravemind



Category: Halo (Video Games) & Related Fandoms
Genre: Alternate Universe - Canon Divergence, Body Horror, Gen, Just in general a lot of manipulation, Logic Plague, Mind Manipulation, Other, Parasites, Tags TBA
Language: English
Status: In-Progress
Published: 2020-08-23
Updated: 2020-08-24
Packaged: 2021-03-06 16:15:27
Rating: Mature
Warnings: Graphic Depictions Of Violence
Chapters: 3
Words: 4,692
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26061763
Author URL: https://archiveofourown.org/users/ProtoGravemind/pseuds/ProtoGravemind
Summary: Ava, a scientist that works for ONI, was one of the scientists aboard the ship known as the Mona Lisa. Eventually, she was assigned with a task kept secret from even the others onboard.
Comments: 1
Kudos: 4





	1. Missing Prisoners

Ava was one of the Section 3 ONI Scientists that worked for Major John Smith. Most of the people described her as.. oddly intrigued by alien life forms, trying her best to understand and "dissect" their actions, which sounded weird in hindsight, but her knowledge on topics and her skills as a fast learner were not something to blink at.

She was aware that something had changed aboard the ship, however, shortly after her superior took command. Apparently, the prior group in charge of commanding the vessel had vanished, leaving only ONI scientists, and prisoners of both Sangheili and Human descent, some of which were new prisoners, gathered by the marines on board during missions prior to Smith taking over. They were never given clear orders on what to do with the prisoners, but it seemed as if they would start going missing at random.

She was the first to notice it, but not the first to speak up about it. As a matter of a fact, she was quite afraid to. She had heard rumors about Smith having a rather stern and sometimes violent temper, after all. In the first place, should she even be worried about the lives of some prisoners, though?

Probably not. If she did, she'd end up worrying herself sick over something that didn't even include her area. She was a scientist, after all. The marines would probably take care of it if it was something major like escapees, right? Taking a deep breath, she would sigh- getting back to her usual work.

The rest of the day continued without much hindrance- she would do her research with the help of the other scientists, and submit the work to the proper places, and quite honestly she had no clue if anything was actually being sent anywhere. There weren't supply ships for days, and while her mind would wander to the chances of communication with the outside being cut off, she tried to forget about that.

Her alarm went off at her desk, signifying it was time for a break. For once, she acutally left the lab to wander around the ship, mostly since the Mona Lisa was the first spacecraft she had ever set foot on. It was incredibly large, and honestly if she didn't know better she'd assume that it was more of a space station than anything else. She could tell that at some point they stopped moving around and were adrift somewhere, but the ship lacked many windows to see out of for sure.

"Hey... Ava!" She eventually heard a voice calling out to her. It was one of her childhood friends and co-workers, Kelly. Ava gave a small wave in response, smiling awkwardly. She wasn't exactly the type to talk to people as energetically as her co-worker, despite seemingly having a lot of friends- or people who thought they were friends. Shortly after the odd greeting, Kelly went up to Ava, still oddly cheerful about something.

"Wanna see something cool?" She would ask, which confused Ava slightly- she thought that everything aboard the ship was boring and bleak, but apparently not if someone like Kelly could be so overjoyed by it. "Uh... alright," Ava started, only for her hand to be grabbed as she was pulled off in the direction of the recreation room.

Ava had never been on this part of the ship, so she wasn't aware of it nor the windows that were present within it- giving a clear outlook on their current location to a point. The windows were still rather small despite everything, due to the fact that the ship WAS a civilian prison ship and not a ship used for cruises or battle.

Upon glancing out of the window, she could make out something glowing orange amidst the blackness of space. It appeared to be metal, and the colors she saw seemed to be the remains of the destroyed "Halo" ring- but of course she wouldn't know about that too much, she was seemingly not kept up on too much of the religious aspects of the Covenant or the war that was happening in the background of their lives.

Thus, Ava tilted her head, "What's that?"

"It's clearly some sort of alien structure, you're the smart one here so I thought you'd know about it!" Kelly would respond, leading to Ava frowning, turning to look at her co-worker, "I may be smart with some things, but I don't know about this... I think." 

Kelly would snicker a bit, before looking around for a bit, "It's strange, though. A group of scientists aboard a prison ship int he middle of space? What if something bad happens like we get attacked by the Covenant? I don't quite know how to use a gun properly, let alone anything military grade--" She was soon interrupted by Ava.

"I don't think it'll get bad for us. If anything happens, I'm sure that Smith will send out some sort of distress call."

Ava was going to find out that probably wouldn't be the case, but now was not the time- instead, Kelly would simply take a moment to shrug off the fact that she was rather afraid of dying to some aliens, and brought up something else that caught Ava's attention more-

"Apparently they're picking out a select few of us for some secret project too. Don't know much about it, but apparently it's dealing with something big that could help us win any battle! That's... all I know about it, but imagine if one of us ends up being chosen for it?"

Ava tilted her head, "Well, That seems interesting, but--"   
"I also saw one of the ship's Pelicans fly out towards the wreckage out there as well..." Kelly then stated, "It came back just a bit ago, so maybe we'll get our answers soon."

While Ava was rather excited about all this, a part of her was, for the most part, nervous. Gathering something from a broken structure for experimentation? The lack of information was making her curiosity spike along with her interest in the topic.

Questioning others aboard lead to her finding out that the Pelicans have been going back and forth since a few days ago, which was also around the time the prisoners started to go missing. Perhaps she was overthinking it, but if the two situations were related...

Things were about to get really interesting.

**Notes for the Chapter:**

> Sorry for how short it is. The first chapter is mainly meant to set some foundation for the plot. This is also my first time writing a story that I intended to post publicly, so I do apologize for any errors on my part!


	2. The Secret

As expected, she was chosen to be the one to work on the newly-found project of the ship that she was aboard. Ava wasn't sure wither to be excited or not when she was directly approached by Smith, who looked much more serious than usual.

"Ava." He would start, "You are by far the smartest person on this ship and the quickest when it comes to learning about new things. For this reason, I need you to come with me." This alone would cause Ava to pause, seeming to avoid eye contact for a moment as this was probably her first time being addressed in such a manner directly.

Taking a moment to recollect herself, Ava looked at the other, "Thank you, Major Smith. I will do my best. Please lead the way." Trying her best to sound professional, despite the fact that she was usually very awkward at any form of communication that wasn't towards things that weren't obviously human. He would then turn, leading the way to an elevator onboard the ship that took the two down a few floors. For the most part, Ava was getting the feeling of nervousness from the secrecy already being kept around the topic, as well as the disappearances..

The elevator doors opened after a bit, revealing a path that lead to what appeared to be another repurposed part of the ship. The doors looked to be recently upgraded via salvaged parts, but ultimately the whole entrance was akin to the kinds of things you see before entering a place that contained hazardous materials.

"I will leave you to do as you will until I return. Your objective is to study what is within that room." He turned, making one last statement to Ava before heading back into the elevator- "Try not to die, if you can."

Ava could only stand there, obviously dumbstruck by the other's statement. What could possibly be in that room that is that bad? It couldn't be too dangerous, right? Perhaps just some weird alien species right?

Wrong.

Upon entering the room, the doors sealed behind her instantly. What she saw moments later appeared to be a growth of some sort, and it had spread throughout most of the room. Amidst the overgrown room, there were corpses along with about three strange creatures that kind of reminded her of odd pillows. They were probably about to her knees in height, with strange 'feelers' extending from their bioluminescent green and tan bodies. They had many, legs, and honestly almost reminded her of spiders in a way.

It wasn't long before the creatures seemed to take notice of her though, all three of them seeming to clumsily skitter up to her, causing her to back up against the door nervously. "A-ah, uh-" She would start, feeling her heartbeat quicken- "- Nice... little things, uh-"

Her voice was shaky, and she tried to recompose herself only to have one of the three creatures start to rub its feelers against her leg. Squinting a bit, Ava watched before the thing seemed to simultaneously latch onto her leg and climb up her. A small squeak of fear from the sudden decision of the lifeform caused her to stumble a bit slipping on a bit of the strange, fleshy floor. At least it didn't hurt.

What did slightly, however, was the 'nibbling' of the creatures that were in the room with her. Attempting to pull the strange creatures off, she would frown at them before attempting to locate the marks in which she was bit. From the qualities of it she was observing, along with the fact that the bites weren't that deep, she could easily assume that the creatures were certainly not meant for killing. As a matter of a fact, the creatures themselves seemed rather fragile- and would probably be unable to break through shields or reinforced clothing without a lot of effort, and potentially die in the process.

At some point, however, the three that were in the room started to scuttle around aimlessly, even seeming to chase eachother in circles at a point. Ava found herself watching, intrigued by the way that the creatures were acting, for they seemed to be a bit on the harmless side for a good moment... that was, until someone else entered the room. Surprisingly, it wasn't Smith despite his voice being heard. It appeared to be one of the prisoners, in which caused Ava to get rather worried.

For the most part, he seemed unconscious. This would have been fine if the three creatures didn't instantaneously latch onto his body and start gnawing away, eventually slowly killing the man in his seemingly drug-induced sleep. From there, one of the creatures seemed to burrow into the corpse's chest, creating a sort of grotesque hole that soon sprouted the same feelers as the smaller form before had. Ava watched, and to her horror she saw the man that just died get reanimated.

Albeit in the process the body got horribly mangled, the skin seeming to rot and bubble in places as the body struggled to stand up straight. A slimelike green substance dripped from open gashes that were formed in the mutation process, puddling on the floor below as the creature seemed to let out a low, ominous wheeze as the sound of bones cracking accompanied the growth of what appeared to be a claw of some assort from the left arm of the body. It seemed to 'look around', if you could say that, considering the fact what one would consider the head originally was now snapped and off to the side.

Ava seemed to look around, frantic for a moment before she hears Smith talking to her over a small intercom- assuming he was outside. "That is The Flood." He explained, "It's a parasite that we received reports of existing here. It's highly contagious and dangerous, but we don't know much about it other than that. I am looking for a way to weaponize it, and you are going to help me. You're seemingly special, after all." He continued.

Her response was a rather dumbfounded gaze at the protective glass that Smith was observing from, to which he continued to speak, "Under normal circumstances upon entering you probably would have instantly died much like that man. As I suspected, though, you seem to be quite different when it comes to this situation. That's why I am assigning you to this task. I will provide you with the supplies you need to study and research this parasite." He sounded so serious about the matter at hand, and honestly, Ava was quite confused herself.

How come she didn't receive the same fate as the other that was thrown into the room? And on top of that, why hasn't the creature that the person turned into attacked her at all? There were so many questions she had, but no one to ask them to. Other than the low growls from the once-human in front of her and the noises of the other two infection forms, there was nothing. 

At some point she assumed Smith left again, so it was no use asking him questions. Sitting in a corner, she guessed she'd not be allowed to leave with this knowledge- considering how 'top secret' it seemed, even from the others aboard the ship itself. Ava could understand why, though, this thing had proven to attack on sight and was capable of parasitic infection of bodies- probably regardless of the state of living.

Eventually, she seemed to do something odd though, an attempt she deemed wouldn't have any sort of fruitful results. Taking a breath in, she would attempt at communication with the parasite in front of her- albeit first simply through her obviously fearful voice-

"C...Can you... speak?" Ava managed to say, an obvious fear present in her tone and body language as she did so, her hands fidgeting together as she averted her gaze. "... That's probably silly to ask, right? You seem to just make little sounds."

A small pause, "Maybe you're shy, though? If you can speak I mean... Perhaps you're not as bad as you come off to be? Perhaps you just do what you do to survive? Maybe... you feel trapped here?" 

No response for a moment.  
Though just as Ava was about to speak again, the combat form seemed to point at her with its large, clawed appendage. That alone was enough to startle her and push her back against the wall, her mind spiraling into possible thoughts of the other creature actually understanding her. What if these weren't just 'mindless parasites' anyways? "U-uh..." She stammered, holding her head slightly as if she was dizzy. 

At some point, though, she seemed to pass out.


	3. For the Best

**Summary for the Chapter:**

> Ava decides to help the parasite after striking a deal that will supposedly help her as well.

" _Wake up._ "

A voice startled the scientist, and she could tell that it was not anyone she knew- it was deep, slow, and filled her with an overwhelming sense of dread. The room's state had gotten worse since the time she entered, nearly reaching to the door from the corner it originated in. Strange growths akin to pouches had formed on some of the more clearly overgrown walls, and what appeared to be tendrils hung down from the ceiling slightly. Whatever this parasite was, she felt this small room would certainly not contain it for long. Looking at her arms, she realized that she was still in tact- her body was still human, and that alone was enough to cause her to take a sigh of relief before feeling something crawling on her.

Jumping a bit, reaches up only to gently pat at the strange body of one of the Infection Forms that were in the room. There were more now, most of them rather aimlessly moving around. The Combat form from earlier appeared to be gone, but she didn't really think much of it at the time. 

"Ava?"

A much more familiar voice was heard- it was Smith this time. Of course, Ava took no time to question the OTHER voice though, "Did you have a filter on your voice earlier? You sounded really scary." Smith furrowed his brow, though she could certainly not see that.

"No? Ava, are you by chance hearing things?" He would question, "I need you to be honest with me."

Ava seemed to hesitate. "It was nothing." She eventually would say, "Anyways, I uh... was wondering, The stuff in here seems to have grown more. Is that bad?" 

Smith would scoff a bit, as if he expected her to know better by now- "I left you in there to observe what it does so we could weaponize it, and apparently you've learned nothing? I'm disappointed."

This registered in Ava's mind shortly after as 'a failure', which was something she didn't really take kindly to being called. Her tone suddenly shifting, she seemed to end up speaking in a more solemn tone, "I'm sorry, sir. I can do better now, please give me more time."

"Of course." He would respond, "The only way you're getting out of there is if you get me an answer I want, after all. Or if you die- but I'm not seeing that happening any time soon." 

Communications were cut off shortly after, and Ava was alone once again, that is if you didn't include The Flood in the room with her. Taking a moment to try and gather her thoughts, she began to think. Weaponizing something that potentially had a mind of it's own? That was pretty drastic, but considering she saw how a form that looked capable of contact was made out of a human body... then maybe, perhaps....

She would take the infection form off her head, being careful not to apply much pressure since she didn't want to pop it. It wiggled its legs around, feelers attempting to make sense out of why it was no longer on a surface that it could rest on. She sighed, before setting the thing on her lap upon sitting down.

"You know, maybe it'd be cool if you guys were actually capable of talking to me. Maybe I wouldn't be alone in trying to figure out this whole thing. My life probably wont be considerably normal again any time soon, so perhaps I could just embrace the fact that this is happening now."

Ava was, for the most part, talking to herself. She didn't expect any kind of response due to the fact that she was still under the impression that the being that she was interacting with, and studying, was incapable of speech.

Unfortunately, she was wrong. As one would have it, the same voice that told her to wake up seemed to ring in her head, though it had some sort of comforting vibe to it now that she couldn't truly process- it was as if she was a mix of afraid and soothed.

" _We are capable, thanks to you._ "

She felt a shiver go up her spine as she listened to the voice. It was as if it came from all around her, but in reality she was the only one who heard it. Smith wasn't around either, so she couldn't question him about it. Assuming she could respond to the voice, she would swallow what fear she had and go for it. "Are you.... the parasite within the room with me? Are you everything in this room?"

" _Mostly._ " It would respond, " _There are small areas that have not been assimilated yet._ " The fact caused Ava to shudder ever so slightly once again.

"But.... then what about the whole ship. Are you capable of getting out of this room?" She would continue, asking a lot of questions now that she had something to communicate with. " _No. We cannot leave this room, much like you. We are trapped, just like you._ " 

" _But... We feel you can help Us._ " 

Ava seemed to look away. How do you avoid eye contact with something that's in the entire room around her. "I don't think I can do that." She responded, "I already got scolded once for not doing my job well enough, I'm assuming you saw that. I just want to prove that I'm a capable person that can do nice things that help others." She would then continue, looking then at the Infection form in her lap. It seemed to 'tilt' to look up at her in return. "Why didn't you turn me into a monster like you did that other guy that was thrown in here."

" _You are more valuable. That is why We wish to offer you a deal. We can help you impress your superior, and you can help us leave this room._ "

"Is that really a good idea? You're a parasite that I know hardly anything about, and I'm just a person that wants to be seen as anything but a failure."

" _Truly you don't think we will not value your limits as a human. We simply wish to live, to free ourselves from this prison We find ourselves in. Don't you find it unfair how We were trapped and experimented on without consent?_ "

"Well... uh, I guess, but--"

" _Then we will help you 'prove' that you have given Smith his wish of weaponizing Us._ "

Ava took a moment to hold onto her head, clearly feeling conflicted about this all. There was a part of her, no.... most of her wanted to believe the parasite. Something about it just sounded like the perfect opportunity to prove how capable she was.

"Fine. I will take your offer."

Little did she know she was a puppet for something far greater than she could possibly imagine. The first mistake was agreeing to the terms of something like The Flood. The second would take a small amount of time to come to maturity, but it was evident in the sudden mental change in Ava the next day that Smith came to check in on her.

"Ava, I have come to--" Smith started, only to be cut off by an overly excited scientist, "Great news, Smith! I have figured out how to befriend the parasite and I believe I can easily figure out how to use it for our personal gains!"

Smith was silent, almost as if in shock from the scientist's sudden discovery. "But just a day ago, you were..." 

"That was a day ago! I worked hard, you see, and as luck would have it, I achieved greatness. Now, wouldn't it be fair to let me out of this cramped little room?" Ava responded, tilting her head slightly. Smith sighed, "Afraid not, if the Flood spreads from there--"

"I said I have it under control. Do you not understand? We're fine."

"I apologize, but no." Smith would say, turning to head back to the main area of the ship, "Even if you were to weaponize it, I cannot risk the chances of being found out for what has been done here."

Ava fell silent.

The lapse of proper judgement between the two, one of which was not in her right mind fully, was inevitably what lead to the situation that happened soon after.

\---

Kelly was worried about her friend from the start, the sudden disappearance for assisting in studying something top secret. She had been on edge from days after, something a few of the prisoners that she frequently spoke with would easily note. Upon mentioning the testing however, they would fall silent and refuse to say much about it. Perhaps they knew more about the situation than she thought. Most of the crew was kept in the dark.

However, a month after Ava's employment by Smith, the general disappearances suddenly weren't limited to just the prisoners. Kelly was noticing people were going missing from the staff too, seemingly at random at that. Kelly wondered if she was next every day. Sometime after the first few disappearances, they had stopped hearing from Smith as well, and without orders, they were sort of just doing whatever.

At some point, Kelly recalled the other scientists mentioning a strange, putrid smell coming from the direction of the engine room, and hearing strange voices. The rumors about the ship supposedly being haunted originated there, but Kelly would soon find out that is not correct in the slightest, for this was the day she decided to go to the recreation room.

Unbeknownst to her, Ava's presence with the Flood aided in its escape from the haphazardly made quarantine room, and spread with haste throughout the ship, focusing primarily on gathering most of the biomass it had around the engine room. From there, it branched outwards, reaching throughout the ship in mostly unoccupied areas before reaching the very recreation room that Kelly found herself in right now.

And thus ensued a truly awkward interaction.

Kelly, upon entering the room, was met with the image of her once-colleague. At first she didn't recognize her due to the stained, filthy lab coat and the abnormally wide smile on her visage as she turns abruptly from her task of petting a Flood Infection Form to stare at the other girl. "Oh! Kelly!" Ava would say, the parasite's attention becoming locked onto the other girl for a good moment. "Heya! Sorry for being awa--"

Ava was interrupted by Kelly nearly vomiting, which ultimately caused her to frown. "Eh... What's up? Why are you doing that?" Ava would ask, causing Kelly to glare up at the other.

"Wh-What the hell is that!? It reeks, Can't you tell? There's something... growing on the walls..." She managed to say, backing towards the door. Ava's response was to look around and then shrug.

"I'm used to it."

"USED TO IT?!" Kelly then yelled, Ava remained unfazed, but looked at the infection forms shortly after.

"Should we do something about her? She may get annoying." Ava seemed to ask shortly after. Kelly was dumbstruck. This was someone that was her friend not too long ago, and now she was talking to some weird little bug-thing. She would take a step forward, nervously at that, raising out an arm. "Ava... I don't know what's happening, but we're friends, right? You're.... You aren't doing something horrible are you?" 

"What are you talking about?" Ava would then say.

"The only friends I have are the were by my side for the past month."

"What... what do you even MEAN by that, Ava?" Kelly responded, "We've been friends for way longer than you've probably known whatever THAT is."

Ava found herself staring blankly at the other for a few moments, before raising her hand to point at her. There was something of a smirk on her face, Her eyes seeming pretty devoid of emotion otherwise.

"Goodbye."

Kelly could only manage to scream for a second before she was jumped by the infection forms, which began to burrow into her chest, biting and gnawing at her flesh and bones to create a proper opening. Frantic, Kelly would try to stop the process, but in the end she would only just quicken it- after all, snapping your own neck in sheer panic leads to instantaneous death, right?

Well, that may have been for the best.

The body twisted and the bones cracked, skin tearing and festering to make way for the growths of the left claw and rotten, decaying flesh. The reanimated corpse of Ava's previous friend was now a Human-Flood Combat Form, which then rushed off into the other areas of the ship. Ava didn't care. Her mind was totally entranced by the words being spoken to her by what she considered to be her real 'friends'.

The Flood was spreading throughout the ship. Smith never intended for this.   
And it was just going to get worse from here.


End file.
